Note: The helpers cannot access other helpers like the Kendo UI or like Html.TextBox() but there is a work around.
You need to pass the view page into the helper and use page.Html. where you normally just had Html.
Make sure you remember the using's

Above is for a Kendo window but you can use the Fluent builder of any kendo UI.
Also remember its still a builder so you could still add to it like @(Html.CBKendoWindow("Copy Paste", 0, 0).Scrollable(true))